Adapter with centering mechanism for articulation joint

ABSTRACT

A joint assembly of an adapter defines a first longitudinal axis and includes first and second hinges, first and second rings, a joint cover, and a biasing mechanism. The joint cover has first and second cover portions. The first ring is pivotally coupled to the first hinge and the first cover portion is pivotally coupled to the first hinge to define a first joint center. The second ring is pivotally coupled to the second cover portion and the second hinge is pivotally coupled to the second ring to define a second joint center that is spaced from the first joint center. The first and second joint centers define a cover axis of the joint cover. The biasing mechanism is engaged with the first ring and the joint cover to bias the joint cover towards an aligned configuration in which the cover axis is aligned with the first longitudinal axis.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.16/414,939, filed May 17, 2019, now U.S. Pat. No. 10,667,813, which is acontinuation of U.S. patent application Ser. No. 15/449,210, filed onMar. 3, 2017, now U.S. Pat. No. 10,299,790. Each of these disclosuresare incorporated by reference herein in their entirety.

BACKGROUND 1. Technical Field

The present disclosure relates to surgical instruments and, morespecifically, to adapters including centering mechanisms forarticulation joints of surgical instruments.

2. Discussion of Related Art

A number of surgical instrument manufacturers have developed productlines with proprietary powered drive systems for operating and/ormanipulating surgical instruments. In many instances, the surgicalinstruments include a powered handle assembly, which is reusable, and adisposable end effector or the like that is selectively connected to thepowered handle assembly prior to use and then disconnected from thepowered handle following use in order to be disposed of or in someinstances resterilized for re-use.

Generally, adapters of existing surgical instrument translate anddeliver power from the handle assemblies, electro-mechanically ormanually, to the end effectors. The adapters may support an articulationjoint or joints for articulating the end effectors relative to alongitudinal axis of the adapter. To improve accessibility to a surgicalsite, the articulation joints may be configured to articulate the endeffector about a variety of axes in relation to the longitudinal axis ofthe adapter and may include multiple joints or a universal joint toachieve a desired articulation angle for the end effector.

When an articulation joint includes multiple axes of articulation, thedegree of articulation can be difficult to accurately control becausewhen a force is applied to articulate the end effector, the end effectoris articulated about multiple axes simultaneously. In addition, duringactuation of the surgical instrument, the position of the jointsrelative to one another can vary in response to forces which are exertedbetween the handle and the end effector, and which pass through thejoints. There is a continuing need to increase the accuracy of anarticulation mechanism of an adapter supporting an end effector forarticulation about a plurality of axes to maintain the position of thejoints during actuation of the surgical instrument.

SUMMARY

In an aspect of the present disclosure, a joint assembly includes aproximal joint housing, a first hinge, a first ring, a joint cover, asecond ring, a second hinge, and a biasing mechanism. The proximal jointhousing defines a first longitudinal axis and includes the first hingethat is positioned at a distal portion of the proximal joint housing.The first ring is pivotally coupled to the first hinge about a firstpivot axis that is orthogonal to and intersects the first longitudinalaxis. The joint cover has first and second cover portions. The firstcover portion is pivotally coupled to the first hinge about a secondpivot axis that is orthogonal to and intersects the first pivot axis andthe first longitudinal axis. The first and second pivot axes intersectthe first longitudinal axis at a first joint center. The second ring ispivotally coupled to the second cover portion of the joint cover about athird pivot axis. The second hinge is pivotally coupled to the secondring about a fourth pivot axis that is orthogonal to the third pivotaxis. The third and fourth pivot axes intersect at a second joint centerthat is spaced from the first joint center. The cover axis of the jointcover is defined between the first and second joint centers. The biasingmechanism is engaged with the first ring and the joint cover to bias thejoint cover towards an aligned configuration in which the cover axis isaligned with the first longitudinal axis.

In aspects, the biasing mechanism includes a pair of inner biasing barsand a pair of outer biasing bars. The pair of inner biasing bars may beengaged with the proximal portion of the joint cover and the pair ofouter biasing bars may be engaged with the first ring. Each of the innerand outer basing bars of the pairs of inner and outer biasing bars mayextend longitudinally and may be translatable in a direction parallel tothe first longitudinal axis. Each of the inner and outer biasing bars ofthe pairs of inner and outer biasing bars may be operably associatedwith a respective biasing member that is configured to urge theassociated biasing bar through the first hinge.

In some aspects, in the aligned configuration of the second hinge, asecond longitudinal axis is aligned with the cover axis and the firstlongitudinal axis. The second longitudinal axis may pass through thesecond joint center and extend through the center of the second hinge.In a first articulated configuration of the joint assembly, the secondlongitudinal axis may be articulated relative to the cover axis with thejoint cover in the aligned configuration. In a second articulatedconfiguration of the joint assembly, the second longitudinal axis may bearticulated relative to the cover axis and the cover axis may bearticulated relative to the first longitudinal axis. The biasingmechanism may be configured to maintain the joint assembly in the firstarticulated configuration until the second longitudinal axis isarticulated to a maximum angle of articulation relative to the coveraxis. The maximum angle of articulation may be in a range of about 15°to about 45°.

In certain aspects, the joint assembly includes a first drive shaft, ajoint body, and a second drive shaft. The first drive shaft may extendthrough the first hinge. The joint body may have first and second bodyportions. The first body portion may be rotatably disposed within thefirst cover portion and may be rotatably and pivotally coupled to thefirst drive shaft. The second body portion may be rotatably disposedwithin the second cover portion. The second drive shaft may extendthrough the second hinge. The second drive shaft may be rotatably andpivotally coupled to the second body portion. The first drive shaft mayinclude a drive ball that is disposed within the first body portion. Thefirst drive shaft may be rotatably disposed along the first longitudinalaxis. The drive ball may define a center channel that is orthogonal tothe first longitudinal axis and arced slots in a plane that is alignedwith the first longitudinal axis and bisects the center channel.

In particular aspects, the joint assembly includes a center pin and ashaft pin. The center pin may be disposed within the center channel andmay define a pin opening that is orthogonal to a central longitudinalaxis of the center pin. The shaft pin may be disposed within the pinopening and the arced slots to rotatably couple the joint body to thefirst drive shaft. The arced slots and the shaft pin may cooperate tolimit articulation between the first drive shaft and the joint body.

In aspects, the second drive shaft further includes a receiver. Thereceiver may be rotatably disposed within the second cover portion andmay receive the second body portion. The joint cover may define a coveraxis that passes through the first and second joint centers. The secondbody portion may define a center channel that is orthogonal to the coveraxis and arced slots in a plane that is aligned with the cover axis andbisecting the center channel. The joint body may be rotatable along thecover axis.

In some aspects, the joint assembly includes a center pin and a shaftpin. The center pin may be disposed within the center channel and maydefine a pin opening that is orthogonal to a central longitudinal axisof the center pin. The shaft pin may be disposed within the pin openingand the arced slots to rotatably couple the joint body to the seconddrive shaft. The arced slots and the shaft pin may cooperate to limitarticulation between the joint body and the second drive shaft.

In another aspect of the present disclosure, an adapter includes aproximal portion, an elongate portion, and a distal portion. Theproximal portion is configured to couple to a handle. The elongateportion extends from the proximal portion and defines a firstlongitudinal axis. The distal portion is supported by the elongateportion and is configured to releasably couple to a tool assembly to thehandle. The distal portion includes a joint assembly. The joint assemblyincludes a first hinge, a first ring, a joint cover, a second ring, asecond hinge, and a biasing mechanism. The first hinge is disposed alongthe first longitudinal axis and is positioned at a distal end of theelongate portion. The first ring is pivotally coupled to the first hingeabout the first pivot axis that is orthogonal to and intersects thefirst longitudinal axis. The joint cover has first and second coverportions. The first cover portion is pivotally coupled to the firsthinge about a second pivot axis that is orthogonal to and intersects thefirst pivot axis and the first longitudinal axis. The first and secondpivot axes intersect the first longitudinal axis at a first jointcenter. The second ring is pivotally coupled to the second cover portionof the joint cover about a third pivot axis. The second hinge ispivotally coupled to the second ring about a fourth pivot axis that isorthogonal to the third pivot axis. The third and fourth pivot axesintersect at a second joint center that is spaced form the first jointcenter. A cover axis of the joint cover is defined between the first andsecond joint centers. The biasing mechanism is engaged with the firstring and the joint cover to bias the joint cover towards an alignedconfiguration in which the cover axis is aligned with the firstlongitudinal axis.

Further, to the extent consistent, any of the aspects described hereinmay be used in conjunction with any or all of the other aspectsdescribed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the present disclosure are described hereinbelow withreference to the drawings, which are incorporated in and constitute apart of this specification, wherein:

FIG. 1 is a perspective view of an electromechanical system provided inaccordance with the present disclosure;

FIG. 2 is a perspective view of an adapter and a tool assembly of theelectromechanical system of FIG. 1 with the tool assembly in anunclamped position;

FIG. 3 is an enlarged view of the indicated area of detail of FIG. 2with the tool assembly in an aligned position;

FIG. 4 is a perspective view of the tool assembly and a distal portionof the adapter of FIG. 2 in a first articulated position;

FIG. 5 is a perspective view of the tool assembly of FIG. 2 separatedfrom a joint assembly of the adapter of FIG. 2;

FIG. 6 is an exploded view, with parts separated, of the joint assemblyof FIG. 5;

FIG. 7 is a rear perspective view of the joint assembly of FIG. 5;

FIG. 8 is a cross-sectional view of taken along section line 8-8 of FIG.7;

FIG. 9 is a cross-sectional view of taken along section line 9-9 of FIG.7;

FIG. 10 is an enlarged view of the indicated area of detail of FIG. 7;

FIG. 11 is a cross-sectional view taken along section line 11-11 of FIG.5;

FIG. 12 is an enlarged view of the indicated area of detail of FIG. 11;

FIG. 13 is a cross-sectional view taken along section line 13-13 of FIG.11;

FIG. 14 is an enlarged view of the indicated area of detail of FIG. 13;

FIG. 15 is a side view of the joint assembly of FIG. 5 in a alignedposition;

FIG. 16 is a top view of a portion of the joint assembly of FIG. 15;

FIG. 17 is a cross-sectional view taken along section line 17-17 of FIG.16;

FIG. 18 is a top view of the joint assembly of FIG. 16 with a distaljoint of the joint assembly in an articulated position with the cablesremoved;

FIG. 19 is a cross-sectional view taken along section line 19-19 of FIG.18;

FIG. 20 is a side view of the joint assembly of FIG. 15 in anotherarticulated position;

FIG. 21 is a side longitudinal cross-sectional view of the jointassembly of FIG. 20;

FIG. 22 is a perspective view of a proximal portion of the adapter ofFIG. 2 with portions of the adapter shown in dashed lines;

FIG. 23 is a rear perspective view of an articulation assembly of theproximal portion of the adapter;

FIG. 24 is an exploded view, with parts separated, of the proximalportion of the adapter of FIG. 2;

FIG. 25 is a cross-sectional view taken along section line 25-25 of FIG.2;

FIG. 26 is an enlarged view of the indicated area of detail of FIG. 25;

FIG. 27 is a cross-sectional view taken along section line 27-27 of FIG.26;

FIG. 28 is a perspective view of the proximal portion of the adapter ofFIG. 22 with a first housing shell removed and a button separated fromover a locking member.

DETAILED DESCRIPTION

Embodiments of the present disclosure are now described in detail withreference to the drawings in which like reference numerals designateidentical or corresponding elements in each of the several views. Asused herein, the term “clinician” refers to a doctor, a nurse, or anyother care provider and may include support personnel. In addition, theterm “proximal” refers to the portion of the device or component thereofthat is closest to the clinician and the term “distal” refers to theportion of the device or component thereof that is farthest from theclinician. Further, in the drawings and in the description that follows,terms such as “front”, “rear”, “upper”, “lower”, “top”, “bottom” and thelike are used simply for convenience of description and are not intendedto limit the disclosure thereto.

This disclosure relates generally to an adapter for use withelectromechanical surgical system. The adapter includes a joint assemblyhaving proximal and distal joints. The proximal joint is biased to analigned position and is adapted to remain in the aligned position untilthe distal joint reaches an articulation limit. When the distal jointreaches an articulation limit, the proximal joint articulates to permitadditional articulation of the joint assembly. In addition, the proximaljoint is adapted to return to the aligned position before the distaljoint articulates away from the articulation limit.

The adapter also includes an articulation mechanism configured toarticulate the joint assembly. The articulation mechanism includes fourcables that extend from a proximal portion of the adapter to a distalportion of the adapter beyond the joint. The cables are adapted to beretracted and extended to manipulate or articulate the joint assembly.Cables on opposite sides of the joint assembly are associated with oneanother such that as one cable is retracted, the opposite cable isextended to control the position of the distal housing and thus,articulation of the joint assembly.

The adapter further includes a roll mechanism configured to selectivelysecure the distal portion of the adapter in a plurality of positionsabout a longitudinal axis of the adapter.

Referring now to FIG. 1, a surgical system 10 in accordance with thepresent disclosure includes a handle 100, an adapter 200, and a toolassembly 600 (e.g., an end effector, multiple- or single-use toolassembly). The handle 100 is configured for selective connection withthe adapter 200, and, in turn, the adapter 200 is configured forselective connection with the tool assembly 600. Together, the handle100 and the adapter 200 may cooperate to actuate the tool assembly 600.The surgical system 10 may be an electromechanically powered system andthe handle 100 may be electrically powered, e.g., battery powered.

The handle 100 includes a drive mechanism (not shown) that is configuredto drive shafts and/or gear components to perform various operations ofthe electromechanical surgical system 10. In particular, the drivemechanism is configured to rotate a proximal drive shaft 260 (FIG. 23),a first articulation shaft 430 (FIG. 23), and a second articulationshaft 450 (FIG. 23) to actuate the tool assembly 600 and to articulatethe tool assembly 600 relative to a longitudinal axis A-A (FIG. 2) ofthe adapter 200 as described in detail below. For a detailed descriptionof an exemplary powered handle, reference may be made to U.S. PatentPublication No. 2015/0272577 and U.S. Pat. No. 9,055,943. The entirecontents of each of these disclosures are incorporated by referenceherein.

With reference also to FIGS. 2-5, the adapter 200 includes a proximalportion 202, an elongate portion 204, a distal portion 206, and a toolassembly connector 208. The proximal portion 202 is configured to couplethe adapter 200 to the handle 100 (FIG. 1). The elongate portion 204extends from the proximal portion 202 of the adapter 200 to the distalportion 206 of the adapter 200 and defines the longitudinal axis A-A ofthe adapter 200. The distal portion 206 includes a joint assembly 300that is configured to articulate the tool assembly connector 208relative to the longitudinal axis A-A as shown in FIG. 4 and describedin detail below, causing the tool assembly 600 to articulate from anon-articulated position in which a longitudinal axis D-D (FIG. 18) ofthe tool assembly 600 is aligned with the longitudinal axis A-A of theadapter 200 to articulated position in which the longitudinal axis D-Dof the tool assembly 600 is misaligned with the longitudinal axis A-A.The tool assembly connector 208 is positioned distal of the distalportion 206 and is configured to couple the tool assembly 600 to theadapter 200.

With particular reference to FIGS. 3 and 4, the tool assembly 600includes a first jaw member 610 and a second jaw member 620 that aremoveable relative to one another between an open configuration (FIG. 3)and a closed or clamped configuration (FIG. 4). As described in detailbelow, the joint assembly 300 allows for manipulation of the toolassembly 600 between a non-articulated position and a plurality ofarticulated positions. As shown, the tool assembly 600 is configured asa stapler with the first jaw member 610 releasably receiving a staplecartridge 612 having a plurality of staples (not shown) and the secondjaw member including an anvil 622.

Referring to FIGS. 5 and 6, the joint assembly 300 is configured tocontrol articulation of the tool assembly connector 208. The jointassembly 300 includes a proximal joint housing 310, a proximal ring 330,a biasing assembly 340, a joint cover 350, a central drive shaft 360, ajoint body 370, a distal drive shaft 380, a distal ring 386, and adistal joint housing 390.

The proximal joint housing 310 extends along the longitudinal axis A-Aof the adapter 200 such that the longitudinal axis A-A is coaxial with alongitudinal axis of the proximal joint housing 310. The central driveshaft 360 is rotatably disposed along the longitudinal axis A-A of theadapter 200 within the proximal joint housing 310. The joint body 370receives a distal portion of the central drive shaft 360 such that thejoint body 370 rotates in response to rotation of the central driveshaft 360. A portion of the joint body 370 is received within the distaldrive shaft 380 such that the distal drive shaft 380 rotates in responseto rotation of the joint body 370. The joint cover 350 is positionedover the joint body 370 such that the joint body 370 is rotatable withinthe joint cover 350. The proximal ring 330 is pivotally secured about aportion of the joint cover 350 and is engaged by the biasing assembly340 to bias the joint body 370 towards an aligned position as detailedbelow. The distal ring 386 is pivotally secured about a portion of thejoint cover 350 and is secured to the distal joint housing 390 topivotally secure a portion of the joint cover 350 to the distal jointhinge 390.

With additional reference to FIG. 7-14, the proximal joint housing 310is substantially cylindrical and defines a central lumen 322therethrough. The proximal joint housing 310 includes a cylindricalportion 311 and a proximal or first hinge 312. The cylindrical portion311 of the proximal joint housing 310 is sized and dimensioned to bereceived within the elongate portion 204 (FIG. 2) of the adapter 200such that the central lumen 322 of the proximal joint housing 310 iscoaxial with the longitudinal axis A-A of the adapter 200. The proximalhinge 312 is supported on a distal portion of the cylindrical portion311 and is sized to extend distally from the elongate portion 204 of theadapter 200 (FIG. 4). An outer surface of the proximal hinge 312 may bedimensioned to form a contiguous surface with an outer surface of theelongate portion 204. The proximal hinge 312 may form a lip 313 (FIG. 7)about the cylindrical portion 311 that is positioned to engage an outeredge of the elongate portion 204 of the adapter 200 to axially fix theposition of the proximal joint housing 310 relative to other componentsof the elongate portion 204 and prevent the proximal hinge 312 frompassing into an outer tube of the elongate portion 204.

With particular reference to FIGS. 7-9, the biasing assembly 340 isdisposed within the central lumen 322 of the proximal joint housing 310and is engaged with the proximal ring 330 and joint body 370 to bias thejoint body 370 towards a non-articulated or aligned position (FIG. 7).The biasing assembly 340 includes plungers 336, biasing members 338,outer bias bars 342, 344, and inner bias bars 346, 348. The proximaljoint housing 310 defines windows 324 that are each sized anddimensioned to receive a respective biasing member 338 such that aproximal portion of the biasing member 338 is longitudinally fixedwithin the proximal joint housing 310. A distal portion of each of thebiasing members 338 receives a shaft 336 a of a respective one of theplungers 336 (FIG. 11) such that the plunger 336 is urged distally bythe biasing member 338. The proximal joint housing 310 also defines barpassages 316 (FIG. 8) that are sized and dimensioned to receive arespective one of the bias bars 342-348. Each of the bias bars 342-348is slidably disposed within one of the bar passages 316 and includes aproximal portion engaged with a respective one of the plungers 336. Inembodiments, each plunger 336 includes a distal plate 336 b and a shaft336 a extending proximally from the plate 336 b such that the shaft 336a is received within a coil of the respective biasing member 338 withthe distal plate 336 b engaged with a distal portion of the biasingmember 338 as shown in FIG. 11. It will be appreciated that the biasbars 342-348 slide within the bar passages 316 in a directionsubstantially parallel to the longitudinal axis A-A of the adapter 200.

In some embodiments, a proximal portion of the bias bars 342-348includes a wing (e.g., wing 344 a (FIG. 7)) to increase the surface areaof a portion of the bias bar 342-348 positioned to engage a respectiveplunger 336. It is envisioned that the bar passages 316 and therespective bias bar 342-348 may be dimensioned and/or configured toreduce chatter or non-longitudinal movement of the bias bar 342-348within the bar passage 316 as the respective bias bar 342-348 slideswithin the bar passage 316.

Referring to FIGS. 11-15, the outer bias bars 342, 344 are positioned onopposite sides of the proximal joint housing 310, with a distal portionof each of the outer bias bars 342, 344 engaged with the proximal ring330 as shown in FIG. 14. The inner bias bars 346, 348 are positioned onopposite sides of the proximal joint housing 310, with a distal portionof each of the inner bias bars 346, 348 engaged with the joint cover 350as shown in FIG. 12. The proximal joint housing 310 may define barcutouts 326 in the proximal hinge 312 that slidably receive a steppedportion 347 (FIG. 12) of the inner bias bars 346, 348. The outer biasbars 342, 344 are radially offset approximately 90° from each of theinner bias bars 346, 348 such that each of the inner bias bars 346, 348is radially positioned halfway between the outer bias bars 342, 344 andeach of the outer bias bars 342, 344 is radially positioned halfwaybetween the inner bias bars 346, 348 as shown in FIG. 8.

With reference to FIGS. 11-14, the proximal joint housing 310 is coupledto a proximal portion of the of the joint cover 350 such that the jointcover 350 is moveable in two degrees of freedom relative to the proximaljoint housing 310. It will be appreciated that the joint cover 350 isrotatably fixed about the longitudinal axis A-A of the adapter 200relative to the proximal joint housing 310.

With particular reference to FIGS. 10-12, the proximal hinge 312includes opposed flanges 314 (FIG. 10) on opposite sides of the centrallumen 322 of the proximal joint housing 310. The proximal ring 330 ispivotally coupled to the flanges 314. Specifically, each of the flanges314 defines a pin opening 314 a and the proximal ring 310 defines pinopenings 331 that are coaxially aligned with the pin openings 314 a ofthe flange 314. A hinge pin 332 is received within each of the pinopenings 331 and a pin opening 314 a of a respective flange 314 topivotally couple the proximal ring 330 to the flanges 314 of theproximal hinge 312. It will be appreciated that the proximal ring 330pivots relative to the proximal hinge 312 about a pivot axis defined bythe hinge pins 332.

Referring now to FIGS. 6, 13, and 14, the proximal ring 330 is pivotallycoupled to the joint cover 350 by housing pins 334. The proximal ring330 defines pin openings 333 on opposite sides of the proximal ring 330with each of the pin openings 333 positioned approximately halfwaybetween the pin openings 331 as shown in FIG. 6. The joint cover 350defines pin openings 353 that are coaxially aligned with the pinopenings 333. The housing pins 334 are received within the pin openings333 and 353 to pivotally couple the joint cover 350 to the proximal ring330 about a pivot axis defined by the housing pins 334. In embodiments,the pivot axis defined by the housing pins 334 is orthogonal to thepivot axis defined by the hinge pins 332 such that the joint cover 350is moveable in two degrees of freedom relative to the proximal hinge312. Alternatively, other pivot axis orientations are envisioned.

Referring again to FIGS. 11-14, a distal portion of the joint cover 350is coupled the distal joint housing 390 by the distal ring 386 such thatthe distal joint housing 390 is moveable in two degrees of freedomrelative to the joint cover 350. It will be appreciated that the distaljoint housing 390 is rotatably fixed to the joint cover 350 and thus,the proximal hinge 312.

With particular reference to FIGS. 6, 11, and 12, a distal portion ofthe housing cover 350 is pivotally coupled to the distal ring 386 byhousing pins 357 (FIG. 12). The distal ring 386 defines pin openings 387on opposite sides of the distal ring 386. The joint cover 350 definespin openings 355 that are coaxially aligned with the pin openings 387.The housing pins 357 are received within the pin openings 355 and 387such that the joint cover 350 is pivotally coupled to the distal ring386 about a pivot axis defined by the housing pins 357.

Referring to FIGS. 13 and 14, the distal joint housing 390 forms adistal hinge and defines a central opening 394 that is disposed alongthe longitudinal axis A-A of the joint assembly 300 in a non-articulatedor aligned position as shown in FIG. 14. The distal joint housing 390includes opposed flanges 392 (FIG. 6) on opposite sides of the centralopening 394. The flanges 392 are radially offset approximately 90° fromthe flanges 314 of the proximal hinge 312 (FIG. 10) and are pivotallycoupled to the distal ring 386. Specifically, each of the flanges 392defines a pin opening 392 a and the distal ring 386 defines pin openings388 that are coaxially aligned with the pin openings 392 a of theflanges 392. The pin openings 388 of the distal ring 386 are on oppositesides of the distal ring 386 with each of the pin openings 388positioned approximately halfway between the pin openings 387 (FIG. 6).A hinge pin 389 is received within each of the pin openings 388 topivotally couple the distal ring 386 to the distal joint housing 390about a pivot axis defined by the hinge pins 389. It will be appreciatedthat the distal ring 386 pivots relative to the distal joint housing 390about a pivot axis defined by the hinge pins 389. The pivot axis definedby the housing pins 357 is orthogonal to the pivot axis defined by thehinge pins 389 such that the joint cover 350 is moveable in two degreesof freedom relative to the distal joint housing 390.

Referring again to FIGS. 6 and 11-14, the central drive shaft 360, jointbody 370, and distal drive shaft 380 pass through and are rotatablewithin the proximal joint housing 310, joint cover 350, and distal jointhousing 390 such that the distal drive shaft 380 rotates in response torotation of the central drive shaft 360 in a plurality of articulatedpositions of the joint assembly 300. The joint body 370 includes aproximal receiver 372 and a distal ball 374. The proximal receiver 372is disposed within a proximal cavity 354 defined in a proximal portionof the joint cover 350. The central drive shaft 360 includes a driveball 362 that is received within the proximal receiver 372 such that thecenters of the drive ball 362, the proximal receiver 372, and theproximal cavity 354 are coincident with one another. The drive ball 362defines a center channel 364 that passes through the center of the driveball 362 transverse to the longitudinal axis A-A of the adapter 200 andreceives a center pin 368 therethrough. The center pin 368 defines a pinopening 369 that is transverse to a longitudinal axis of the center pin368. The drive ball 362 also defines arced slots 366 that are incommunication with the center channel 364. The proximal receiver 372 ofthe joint body 370 defines pin openings 373. A proximal shaft pin 367passes through the pin openings 373, the slots 366, and the pin opening369 to rotatably fix the central drive shaft 360 to the joint body 370such that the joint body 370 rotates in response to rotation of thecentral drive shaft 360. The arced slots 366 allow for one degree offreedom between the central drive shaft 360 and the joint body 370.

The distal drive shaft 380 includes a distal receiver 382 and a distalshaft 384 that extends distally from the distal receiver 382. The distalreceiver 382 is disposed within a distal cavity 356 defined by the jointcover 350 and receives the distal ball 374 of the joint body 370 suchthat centers of the distal cavity 356, the distal receiver 382, and thedistal ball 374 are coincident with one another. The distal ball 374defines a center channel 375 that passes through the center of thedistal ball 374 transverse to a longitudinal axis of the joint body 370and receives a center pin 377 therethrough. The center pin 377 defines apin opening 378 (FIG. 6) that is transverse to the longitudinal axis ofthe center pin 377. The distal ball 374 also defines arced slots 376(FIG. 6) that are in communication with the center channel 375 and thedistal receiver 382 defines pin openings 383. A distal shaft pin 379passes through the pin openings 383, the slots 376, and the pin opening378 to rotatably fix the joint body 370 with the distal receiver 382such that the distal drive shaft 380 rotates in response to rotation ofthe joint body 370. The arced slots 376 allow for one degree of freedombetween the joint body 370 and the distal drive shaft 380. The arcedslots 366 (FIG. 12) of the drive ball 362 are defined in the same planeas the arced slots 376 of the distal ball 374; however, it iscontemplated that a plane of the arced slots 366 may be radially offsetfrom a plane of the arced slots 376 to allow for allow for multipledegrees of freedom between the distal drive shaft 380 and the centraldrive shaft 360.

Referring now to FIGS. 15-17, the adapter 200 (FIG. 2) includes anarticulation mechanism 400 that manipulates the joint assembly 300. Thearticulation mechanism 400 and joint assembly 300 cooperate to controlarticulation of the joint assembly 300 before, during, and afteractuation of the tool assembly 600 (FIG. 5). For example, when the toolassembly 600 is actuated to clamp tissue, fire staples through theclamped tissue, and/or sever tissue, the articulation mechanism 400 andjoint assembly 300 cooperate to reduce chatter and maintain the positionof the tool assembly 600 in relation to the adapter 200 during the eachfunction of the tool assembly 600.

The articulation mechanism 400 includes cables 402, 404, 406, and 408(FIG. 7) that extend through the elongate portion 204 (FIG. 2) of theadapter 200 from a proximal portion 202 (FIG. 2) of the adapter 200 tothe distal portion 206 (FIG. 2) of the adapter 200. Each of the cables402-408 is slidably disposed within one of four cable grooves 319defined in an outside surface of the proximal joint housing 310 andpasses through a respective one of four cable passages 318 (FIG. 8) inthe proximal hinge 312. Each of the cables 402-408 passes from theproximal joint housing 310 to the distal joint housing 390. Each of thecables 402-408 includes a distal retainer (FIG. 17) (e.g., distalretainer 407 of cable 406 and distal retainer 409 of cable 408) that isreceived within a respective cable receiver 398 defined in the distaljoint housing 390. Receipt of the distal retainers within the respectivecable receivers 398 of the distal joint housing 390 facilitatesapplication of tension to the distal joint housing 390.

The cables 402-408 are radially spaced about the longitudinal axis A-Ato facilitate manipulation of the joint assembly 300 such that thedistal drive shaft 380, which defines a distal drive axis D-D, and thejoint cover 350, which defines a cover axis C-C, can be moved between aplurality of articulated positions relative to the longitudinal axisA-A. As shown, the cables 402-408 are evenly spaced radially, e.g.,approximately 90°, about the outer surface of the joint housing 310 witheach of the cables 402-408 passing approximately halfway betweenadjacent windows 324 (FIG. 15) defined in the cylindrical portion 311.It is contemplated that the cables 402-408 may be unevenly spaced aboutthe cylindrical portion 311.

As described in greater detail below, the articulation mechanism 400translates one cable in response to translation of a diametricallyopposite cable to maintain tension in each cable 402-408 to continuouslyapply tension to the distal housing 390. For example, as thearticulation mechanism 400 draws cable 402 proximally, the articulationmechanism 400 simultaneously releases cable 406 permitting cable 406 tobe drawn distally an amount approximately equal to the amount cable 402was drawn proximally. Likewise, as the articulation mechanism 400 drawscable 406 proximally, the articulation mechanism 400 simultaneouslyreleases cable 402 permitting cable 406 to be drawn distally an amountapproximately equal to the amount cable 406 was drawn proximally. Itwill be appreciated that cable 404 is associated with cable 408 in asimilar manner that cable 402 is associated with cable 406 as detailedabove. By keeping each cable substantially taut, articulation of thedistal drive axis D-D of the distal drive shaft 380 relative to thelongitudinal axis A-A and articulation of the cover axis C-C of thejoint cover 350 relative to the longitudinal axis A-A of the adapter 200can be precisely controlled and maintained.

With reference to FIGS. 15-21, articulation of the joint assembly 300 isdescribed in accordance with the present disclosure. The joint assembly300 has a first or proximal joint 302 and a second or distal joint 304.The proximal joint 302 articulates about a pivot axis passing through acenter point that is coincident with centers of the drive ball 362 ofthe central drive shaft 360, the proximal receiver 372 of the joint body370, the proximal portion of the joint cover 350, and the proximal ring330. The distal joint 304 articulates about a pivot axis passing througha center point that is coincident with centers of the distal ball 374 ofthe joint body 370, the distal receiver 382 of the distal drive shaft380, the distal portion of the joint cover 350, and the distal ring 386.The cover axis C-C passes between the center points of the proximal anddistal joints 302, 304. Each of the proximal and distal joints 302, 304is articulable in two degrees of freedom in response to actuation of thedistal joint housing 390 by the articulation mechanism 400.

The joint assembly 300 has a centered or aligned position in which thedistal drive axis D-D of the distal drive shaft 384 and the cover axisC-C of the joint cover 350 are coaxial with the longitudinal axis A-A ofthe proximal drive shaft 360 as shown in FIGS. 15-17. In the alignedposition, the center points of the proximal and distal joints 302, 304are both disposed along the longitudinal axis A-A. In addition, in thealigned position, planes defined by the proximal ring 330 and the distalring 386 are parallel with one another and positioned orthogonal to thelongitudinal axis A-A of the adapter 200.

Referring now to FIGS. 18 and 19, the joint assembly 300 has a firstarticulated position in which the distal joint 304 is articulated suchthat the distal drive axis D-D is articulated relative to thelongitudinal axis A-A of the adapter 200 and the cover axis C-C of thejoint cover 350 remains aligned with the longitudinal axis A-A. Inaddition, the center points of the proximal and distal joints 302, 304remain disposed along the longitudinal axis A-A in the first articulatedposition. The biasing assembly 340 maintains the joint cover 350, andthus the cover axis C-C, in alignment with the longitudinal axis A-Auntil the distal joint 304 reaches an articulation limit, i.e., theposition in which the distal shaft pin 379 reaches an end of the arcedslots 376 (FIG. 12) of the distal ball 374 to prevent furtherindependent articulation of the distal joint 304, i.e., independent ofthe proximal joint 302.

As shown in FIGS. 18 and 19, the articulation mechanism 400 is actuatedto articulate the distal joint housing 390 to reposition the distaldrive shaft 380 such that distal drive axis D-D defines an anglerelative to the longitudinal axis A-A of the adapter 200 within anarticulation limit of the distal joint 304. As shown, the distal housing390 is articulated in the direction indicated by arrow “X₁” such thatthe distal drive axis D-D is repositioned in relation to thelongitudinal axis A-A. During articulation of the joint assembly 300,the distal joint 304 is articulated and the biasing assembly 340 engagesthe proximal ring 330 and the joint cover 350 to maintain the cover axisC-C in alignment with the longitudinal axis A-A. The biasing assembly340 prevents articulation of the joint cover 350 until the distal joint304 reaches its articulation limit. Specifically, the outer bias bars342, 344 are urged into engagement with the proximal ring 330 tomaintain the joint cover 350 in alignment with the longitudinal axis A-Aabout a first axis, rotation about the pivot axis defined by the hingepins 332, and the inner bias bars 346, 348 are urged into engagementwith the joint cover 350 to maintain the joint cover 350 in alignmentwith the longitudinal axis A-A about another axis, rotation about thepivot axis defined by the housing pins 334. By maintaining the coveraxis C-C of the joint cover 350 in alignment with the longitudinal axisA-A, the biasing assembly 340 maintains the proximal joint 302 in thealigned position. As shown, distal portions of the bias bars 342-348engage the proximal ring 330 and the joint cover 350 with substantiallyplanar surfaces such that a large force is required to initiate rotationof the proximal ring 330 and/or the joint cover 350 to articulate thecover axis C-C from the aligned position. This large force is onlyreached after the distal joint 304 is prevented from furtherarticulation by distal shaft pin 379 reaching an end of the arced slots376. It is contemplated that distal portions of the bias bars 342-348may be arcuate to allow the cover axis C-C to articulate away from thealigned position with reduced force.

FIGS. 20 and 21 illustrate actuation of the articulation mechanism 400to articulate the distal joint housing 390 to a second articulatedposition in which the distal drive axis D-D is repositioned relative tothe longitudinal axis A-A of the adapter 200 to an angle beyond thearticulation limit of the distal joint 304. As shown, the distal housing390 is articulated in the direction indicated by arrow “X₂” such thatthe distal drive axis D-D and the cover axis C-C are repositionedrelative to the longitudinal axis A-A from the position shown in FIG.15. More specifically, when the distal joint 304 is articulated to itsarticulation limit, continued articulation of the distal joint housing390 overcomes the biasing force applied by the biasing assembly 340 ontothe proximal joint 302 such that the inner bias bar 346 compresses itsassociated biasing member 338 and the cover axis C-C of the joint cover350 articulates relative to the longitudinal axis A-A about the proximaljoint 302 in the direction indicated by arrow “X₂”. As the proximaljoint 302 articulates, the other inner bias bar 348 is urged distally byits associated biasing member 338 to translate distally and maintainengagement with the joint cover 350. In addition, the outer bias bars342, 344 are urged distally by associated biasing members 338 tomaintain engagement with the proximal ring 330. By independentlymaintaining each of the bias bars 342-348 in engagement with the jointcover 350 and/or the proximal ring 330, the position of the distal jointhousing 390 is rigidly maintained for a given actuation of thearticulation mechanism 400.

It will be appreciated that the biasing members 338 have a substantiallylinear spring constant and the bias bars 342-348 cooperate to urge thejoint cover 350 and thus, the cover axis C-C, into alignment with thelongitudinal axis A-A. As such, when the articulation mechanism 400 isactuated to return the distal joint housing 390 to the aligned positionsuch that the distal drive axis D-D and the cover axis C-C are movedtowards alignment with the longitudinal axis A-A, the biasing assembly340 returns the cover axis C-C of the joint cover 350 and thus, theproximal joint 302 to the aligned position before the distal drive axisD-D is articulated from its articulation limit towards its alignedposition.

In embodiments, the maximum angle of articulation of the proximal anddistal joints 302, 304 may be equal to one another (e.g., 30°) ordifferent from one another (e.g., the maximum angle of articulation ofthe proximal joint 302 may be greater than or less than the maximumangle of articulation of the distal joint 304). It will be appreciatedthat the maximum angle of articulation of the articulation assembly 300is the sum of the maximum angle of articulation of proximal joint 302and the maximum angle of articulation of the distal joint 304.

By controlling the order of articulation of the proximal and distaljoints 302, 304 (i.e., ensuring that the distal joint 304 articulates toits articulation limit before the proximal joint 302 is articulated andreturning the proximal joint 302 to its aligned position beforearticulating the distal joint 304 towards its aligned position),articulation of the joint assembly 300 is more predictable such that thelocation of the tool assembly 600 (FIG. 2) during articulation is morepredictable. In addition, the biasing of the joint cover 350 intoalignment with the longitudinal axis may provide a more stable and rigidjoint assembly 300 by automatically adjusting for cable stretch toreduce cable backlash in the joint assembly 300. Further, by providingconstant tension on the distal joint housing 390 from each of the cables402-408, chatter experienced during actuation of the tool assembly 600can be minimized.

Referring now to FIGS. 22-27, the proximal portion 202 of the adapter200 includes a connector 220, the articulation mechanism 400, and a rollmechanism 500. The connector 220 is secured to the proximal portion 202of the adapter 200 and releasably couples the adapter 200 to the handle100 (FIG. 1). The handle 100 is configured to selectively rotate aproximal drive shaft 260 and to manipulate the articulation mechanism400 when the connector 220 is releasably coupled to the handle 100. Theproximal drive shaft 260 extends along the longitudinal axis A-A of theadapter 200 and extends through the elongate portion 204 to effectrotation of the central drive shaft 360 (FIG. 6). The elongate portion204 also includes a central tube 280 that is coaxially disposed aboutthe proximal drive shaft 260 and an outer tube 270 coaxially disposedabout the central tube 280 to define a channel 272 therebetween.

The articulation mechanism 400 manipulates the cables 402-408 toarticulate the joint 300 relative to the longitudinal axis A-A. Withparticular reference to FIG. 23, the articulation mechanism 400 includesan articulation body 410, a first or upper spindle assembly 420, a firstarticulation shaft 430, a second or lower spindle assembly 440, and asecond articulation shaft 450. The upper spindle assembly 420 and thelower spindle assembly 440 are rotatably supported on the articulationbody 410 about a spindle axis S-S that is transverse to the longitudinalaxis A-A. The upper spindle assembly 420 is disposed on the upper sideof the articulation body 410 and the lower spindle assembly 440 isdisposed on the lower side of the articulation body 410.

With particular reference to FIG. 24, the upper spindle assembly 420includes an inner spindle 422, an outer spindle 426, and a gear 428. Theinner spindle 422 is substantially cylindrical and defines a helicalgroove 423 (FIG. 23) along an outer surface of the inner spindle 422.The inner spindle 422 includes a keyed protrusion 424 that extendstowards the articulation body 410 and is disposed about an upper race414 of the articulation body 410. The upper gear 428 defines a keyedopening 429 that receives the keyed protrusion 424 such that the innerspindle 422 rotates in response to rotation of the upper gear 428. Theouter spindle 426 is substantially cylindrical and defines a helicalgroove 427 (FIG. 23) about an outer surface of the outer spindle 426.The outer spindle 426 includes an upper protrusion 425 that is rotatablyreceived within a spindle recess 518 of the roll body 510. The roll body510 retains the upper spindle assembly 420 over the upper race 414. Theouter spindle 426 is rotatably fixed relative to the inner spindle 422such that the outer spindle 426 rotates in response to rotation of theinner spindle 422. It is contemplated that the inner and outer spindles422, 426 may be monolithically formed with one another. The helicalgrooves 423, 427 of the inner and outer spindles 422, 426, respectively,may form a single continuous helical groove.

The lower spindle assembly 440 includes an inner spindle 442, an outerspindle 446, and a gear 448. The inner spindle 442 is substantiallycylindrical and defines a helical groove 443 (FIG. 23) about an outersurface of the inner spindle 442. The inner spindle 442 includes a keyedprotrusion 444 that extends towards the articulation body 410 and isdisposed about a lower race 416 of the articulation body 410. The lowergear 448 defines a keyed opening 449 that receives the keyed protrusion444 such that the inner spindle 442 rotates in response to rotation ofthe lower gear 448. The outer spindle 446 is substantially cylindricaland defines a helical groove 447 (FIG. 23) about an outer surface of theouter spindle 446. In embodiments, the outer spindle 446 includes alower protrusion 445 that is rotatably received within a spindle recess518 of the roll body 510. The roll body 510 retains the lower spindleassembly 440 over the lower race 416. The outer spindle 446 is rotatablyfixed relative to the inner spindle 442 such that the outer spindle 446rotates in response to rotation of the inner spindle 442. It iscontemplated that the inner and outer spindles 442, 446 may bemonolithically formed with one another. The helical grooves 443, 447 ofthe inner and outer spindles 442, 446, respectively, may form a singlecontinuous helical groove.

Referring back to FIGS. 22 and 23, the cables 402-408 extend from theproximal joint housing 310 (FIG. 6) of the joint assembly 300 to theproximal portion 202 of the adapter 200 through the channel 272 (FIG.22) of the outer tube 270. As the cables 402-408 pass through thechannel 272, the cables 402-408 are guided through holes 282 defined ina proximal cylinder 282 of the central tube 280. The cables 402 and 406are guided through holes 284 on a first or upper side of the proximalcylinder 282 and the cables 404 and 408 are guided through holes 284 ona second or lower side of the proximal cylinder 282. The cables 402-408pass through the holes 284 of the proximal cylinder 282 and into holes512 of a roll body 510. The cables 402-408 pass through the holes 512 ofthe roll body 510 and into holes 412 defined in the articulation body410 such that the cables 402, 406 are disposed on an upper side of thearticulation body 410 and the cables 404, 408 are disposed on a lowerside of the articulation body 40.

With particular reference again to FIG. 23, the cables 402, 406 passfrom the holes 412 defined in the articulation body 410 and into thegrooves 423, 427 of the upper spindle assembly 420 in oppositedirections from one another. As shown, the cable 402 exits a hole 412 ona first side of the upper spindle assembly 420 and enters the groove 427of the outer spindle 426. The cable 406 exits a hole 412 on a secondside of the upper spindle assembly 420 and enters a groove 423 of theinner spindle 422. As the upper spindle assembly 420 rotates in a firstdirection (e.g., counter-clockwise when viewed from above in FIG. 23)the cable 402 is wound about the outer spindle 426 to retract or drawthe cable 402 and the cable 406 is, simultaneously, unwound from aboutthe inner spindle 422 to extend or release cable 406. As the upperspindle assembly 420 rotates in a second direction opposite the firstdirection (e.g., clockwise when viewed from above in FIG. 23) the cable402 is unwound from about the outer spindle 426 to extend the cable 402and the cable 406 is, simultaneously, wound about the inner spindle 422to retract the cable 406. It will be appreciated that this correspondingretraction and extension applies tension to the distal joint housing 390(FIG. 17) to articulate the joint 300 as detailed above.

The cables 404, 408 pass from the holes 412 defined in the articulationbody 410 and into the grooves 443, 447 of the lower spindle assembly 440in opposite directions from one another. As shown, the cable 404 exits ahole 412 on a first side of the lower spindle assembly 440 and entersthe groove 443 of the inner spindle 442. The cable 408 exits a hole 412on a second side of the lower spindle assembly 440 and enters a groove447 of the outer spindle 446. As the lower spindle assembly 440 rotatesin a first direction (e.g., counter-clockwise when viewed from above inFIG. 23) the cable 404 is wound about the inner spindle 442 to retractthe cable 404 and the cable 408 is, simultaneously, unwound from aboutthe outer spindle 446 to extend cable 408. As the lower spindle assembly440 rotates in a second direction opposite the first direction (e.g.,clockwise when viewed from above in FIG. 23) the cable 404 is unwoundfrom about the inner spindle 442 to extend the cable 402 and the cable406 is, simultaneously, wound about the outer spindle 446 to retract thecable 408. It will be appreciated that this corresponding retraction andextension applies tension to the distal joint housing 390 (FIG. 17) toarticulate the joint 300 as detailed above.

With reference to FIGS. 24 and 27, the first articulation shaft 430includes a gear 434 that is meshingly engaged with the gear 428 of theupper spindle assembly 420 to rotate the upper spindle assembly 420about the spindle axis S-S in response to input from the handle 100(FIG. 1). The handle 100 rotates the first articulation shaft 430 abouta shaft axis that is parallel to and offset from the longitudinal axisA-A. The first articulation shaft 430 includes an input portion 432 thatextends through an input hole 438 defined in the connector 220 and mayinclude a bearing assembly 436 disposed about a proximal portion of thefirst articulation shaft 430 to rotatably mount the input portion 432within the input hole 438 and/or to longitudinally bias the firstarticulation shaft 430.

The second articulation shaft 450 includes a gear 454 that is meshinglyengaged with the gear 448 of the lower spindle assembly 440 to rotatethe lower spindle assembly 440 about the spindle axis S-S in response toinput from the handle 100 (FIG. 1). The handle 100 rotates the secondarticulation shaft 450 about a shaft axis that is parallel to and offsetfrom the longitudinal axis A-A. The second articulation shaft 450includes an input portion 452 that extends through an input hole 458defined in the connector 220 and may include a bearing assembly 456disposed about a proximal portion of the second articulation shaft 450to rotatably mount the input portion 452 within the input hole 458and/or to longitudinally bias the second articulation shaft 450.

With reference to FIGS. 22, 24, 26, and 28, the roll mechanism 500 isconfigured to rotate or roll the elongate portion 204 and the distalportion 206 of the adapter 100 (FIG. 2) about the longitudinal axis A-A.An example of a similar roll mechanism is described in U.S. patentapplication Ser. No. 15/229,220, filed Aug. 5, 2016, the entire contentsof which are hereby incorporated by reference.

The roll mechanism 500 includes the roll body 510, a roll housing 520,and a locking mechanism 560. The roll body 510 is rotatably fixed to thearticulation body 410 and the connector 220. The roll housing 520 isrotatably disposed about the roll body 510 with the locking mechanism560 disposed within the roll housing 520. As will be described infurther detail below, the locking mechanism 560 has a locked position(FIG. 3) in which the roll housing 520 is rotationally secured relativeto the connector 220 and an unlocked position (FIG. 13) in which theroll housing 520 is rotatable about the longitudinal axis A-A inrelation to the connector 220. The tool assembly 600 is rotatably fixedto the distal portion 206 of the adapter 100 which is rotatably fixed tothe roll housing 520 such that rotation of the roll housing 520 aboutthe longitudinal axis A-A of the adapter 100 causes the tool assembly600 (FIG. 1) to rotate about the longitudinal axis A-A. This enables aclinician to orient the tool assembly 600 relative to the handle 100(FIG. 1) without changing the orientation of the handle 100.

The roll housing 520 may be formed from a first body shell 524 and asecond body shell 526. Each of the first and second body shells 524, 526form approximately half of the roll housing 520 and may be joinedtogether by fasteners (not explicitly shown). Alternatively, the firstand second body shells 524 and 526 may be secured together by welding orthe like. The first and second body shells 524, 526 define a cavity 522that receives the roll body 510 which is coupled the central tube 280.The central tube 280 is rotatably fixed to the roll body 510. Theconnector 220 includes an annular flange 228 and the first and secondbody shells 524, 526 define a proximal annular groove 528 that isconfigured to receive the annular flange 228. The annular flange 228longitudinally secures the roll housing 520 relative to the connector220 while allowing the roll housing 520 to rotate about the connector220, the roll body 510 and the central tube 280.

With particular reference to FIGS. 22 and 24, the roll body 510 includesa locking race 514, a spacer 515, and a neck 516. Each of the lockingrace 514, the spacer 515, and the neck 516 are substantially cylindricalin shape and are coaxially disposed about the longitudinal axis A-A. Inaddition, each of the locking race 514, the spacer 515, and the neck 516are positioned distal to the recess 518 defined by the roll body 510.The locking race 514 is positioned between the spacer 515 and the neck516. The spacer 515 defines a gap “G” between the locking race 514 and aproximal portion of the roll body 510. The neck 516 distally extendsfrom the locking race 514. The locking race 514 has a diameter greaterthan the neck 516 and less than the spacer 515. The holes 512 thatreceive the cables 402-408 extend through the neck 516, the locking race514, and the spacer 515.

The roll mechanism 500 includes a locking disc 540 and a roll nut 550.The locking disc 540 is disposed about the locking race 514 and isrotationally fixed to the spacer 515 such that the gap “G” is definedbetween the locking disc 540 and the proximal portion of the roll body510. The roll nut 550 is disposed about the neck 516 with a proximalportion 274 of the outer tube 270 disposed between the roll nut 550 andthe neck 516. The roll nut 550 is rotatable relative to the neck 516such that the roll nut 550 rotates about the longitudinal axis A-A. Theproximal portion 274 of the outer tube 270 defines opposed notches 274and the roll nut 550 includes opposed protrusion 552 that are disposedin the notches 274 such that the outer tube 270 rotates in response torotation of the bearing 500 about the longitudinal axis A-A. The rollnut 550 also defines a keyway 554 that receives a key 527 of the secondbody shell 526 to rotatably fix the roll nut 550 to the roll housing 520such that the roll nut 550 and the outer tube 270 rotate about thelongitudinal axis A-A in response to rotation of the roll housing 520 asshown in FIG. 26. As detailed above, the joint 300 and thus, the toolassembly 600 (FIG. 1) are coupled to the outer tube 270 such that thejoint 300 and the tool assembly 600 cooperate with rotation of the rollhousing 520 about the longitudinal axis A-A. The roll nut 550 alsoincludes a landing 556 opposite the keyway 554.

Continuing to refer to FIGS. 22, 24, and 26, the locking mechanism 560engages the locking disc 540 to secure the roll housing 520 in fixedrotational orientation relative to the connector 220. In particular, thelocking disc 540 defines a plurality of lock cutouts 542 that areconfigured to receive a locking member 562 of the locking mechanism 560as described in greater detail below to retain the roll housing 520 inone of a plurality of fixed positions in relation to the connector 220.As shown best in FIG. 22, the lock cutouts 542 are spaced radially aboutthe locking disc 540. It is envisioned that the locking disc 540 maydefine any number of lock cutouts 542 which may be arranged in anysuitable configuration. For example, the lock cutouts 542 may bearranged in set intervals, uniformly or randomly spaced. In addition,the lock cutouts 542 may be formed to extend entirely around the lockingdisc 540 to permit locking of the roll housing 520 in any three-hundredsixty degree (360°) orientation about the connector 220.

With additional reference to FIG. 28, the locking mechanism 560 includesthe locking member 562, a button 580, and biasing members 598. Thelocking member 562 includes a lock body 564, a distal leg 566, and aproximal leg 568. The lock body 564 includes a finger 572 that extendsover the distal leg 566 and bosses 574 that extend from sides of thelock body 564. The distal leg 566 includes a stop 567 and a lock 569.The stop 567 slides along the landing 556 of the roll nut 550 and formsa T-shape with the distal leg 566. The stop 567 has a width greater thanthe width of the lock cutouts 542 such that the stop 567 prevents thedistal leg 566 from passing entirely through the lock cutouts 542.Additionally or alternatively, the lock 569 may engage a back plate 544of the locking disc 540 to prevent the distal leg 566 from passingentirely through the lock cutouts 542. The lock 569 is sized anddimensioned to be positioned within a respective one of the lock cutouts542 when the locking member 562 is in a locked position to preventrotation of the roll housing 520 relative to the connector 220. The lock156 extends proximally from the distal leg 566 and is configured suchthat when the lock 156 is positioned in a respective one of the lockcutouts 542, the stop 567 abuts the locking disc 540. The proximal leg568 includes a foot 571 that is positioned within the gap “G” defined bythe stop 515 of the roll body 510. The distal leg 566 and the proximalleg 568 define a void 574 therebetween that is sized and dimensioned toallow the locking disc 540 to rotate within the void 574 when thelocking member 562 is in an unlocked position as shown in FIG. 26.

The button 580 has a button body 582 that defines blind holes (notshown), an opening 583, and camming slots 584. The opening 583 extendsinward from a bottom surface 582 a of the button body 582 to define adistal opening 583 a in a distal surface 582 b of the body 582. Thedistal opening 583 a includes a shelf 583 b opposite the bottom surface582 a of the button body 582. The blind holes extend substantiallyvertically from the bottom surface 582 a of the button body 582 oneither side of the opening 583 in a direction orthogonal to a planedefined by the bottom surface 582 a. The blind holes may besubstantially cylindrical and are sized to receive the biasing members598.

The camming slots 584 pass entirely through side surfaces 582 d of thebutton body 582. The camming slots 584 extend from a first end 584 a ofthe button body 582 adjacent the bottom surface 582 a of the button body582 and a proximal surface 582 e of the button body 582 to a second end584 b of the button body 582 adjacent the distal surface 582 b and a topsurface 582 c of the button body 582 such that the cam slots 584 areinclined distally upward when the button 580 is viewed in profile. Thecamming slots 584 are in communication with the opening 583 andconfigured to receive the bosses 574 of the locking member 562 such thatvertical movement of the button 580 (i.e., movement substantiallytowards and away from the longitudinal axis A-A) affects longitudinaltranslation of the locking member 562 as described in detail below.

The locking mechanism 560 is disposed in a channel 521 defined in theroll housing 520. The locking mechanism 560 is positioned on theconnector 220 adjacent the locking disc 540. In a locked position of thelocking mechanism 560, the lock 569 is disposed within one of the lockcutouts 542 defined in the locking disc 540 to rotatably fix theorientation of the roll housing 520 relative to the connector 220. Thebutton 580 is positioned radially outward of the locking member 562 suchthat the lock body 564 of the locking member 562 is disposed within theopening 583 of the button 580. When the lock body 564 is disposed withinthe opening 583, the bosses 574 of the locking member 562 are slidinglyreceived within the cam slots 584. In addition, the biasing members 598are received within the blind holes to urge the button 580 away from thelocking member 562. In this position, the locking member 562, due toengagement with the portion of the button 580 defining the cam slots584, is urged proximally to the locked position. The biasing members 598are supported on ledges 568 of the roll nut 550 which are adjacent thelanding 556 to bias the button 580 away from the locking member 562.However, it is contemplated that the biasing members 598 may besupported by and be slidable along a top surface of the stop 567.

The finger 572 of the locking member 562 extends distally within theopening 583 of the button 580 such that the finger 572 is positionedover the shelf 583 b of the button 580 to retain the button 580 withinthe channel 521 of the roll housing 520. In addition, the proximalsurface 581 e of the button 580 can include a retention hook 589 thatextends proximally from the proximal surface 581 e of the button 580into engagement with the roll housing 520 to retain the button 580within the channel 521.

As shown in FIGS. 22 and 28, in the locked position of the lockingmechanism 560, the button 580 is urged upwardly by the biasing members598 such that the locking member 562 is cammed by the bosses 574 to aproximal position. In the proximal position, the lock 569 is positionedwithin a lock cutout 542 of the locking disc 540 to prevent rotation ofthe roll housing 520 in relation to the connector 220.

As shown in FIG. 26, to transition the lock mechanism 560 to theunlocked position, the button 580 is depressed within the channel 521 ofthe roll housing 520 against the bias members 598. As the button 580 isdepressed, the button 580 is confined to substantially vertical movement(movement towards and away from the longitudinal axis A-A) within thechannel 521 of the roll housing 520. As the button 580 is depressed, thebosses 574 slide within the cam slots 584 to affect distal longitudinalmovement of the locking member 562 relative to the roll housing 520.Specifically, walls defining the cam slots 584 engage the bosses 574 totranslate the locking member 562 in a direction substantially parallelto the longitudinal axis A-A. As the locking member 562 moves distallyrelative to the button 580, the lock 569 moves from within a cutout 542to a position distal of the locking disc 540, and thus out of the lockcutout 542. In this position, the roll housing 520 is free to rotateabout the connector 220. As the locking member 564 moves distally, thefoot 571 of the proximal leg 568 slides within the gap “G” defined bythe spacer 515 and may abut the locking disc 540 to limit distalmovement of the locking member 564. In embodiments, contact between thefoot 571 of the locking member 564 and the locking disc 540 may providetactile feedback to a clinician that the button 580 is fully depressedand/or that the locking mechanism 560 is in the unlocked position. Inaddition, when the button 580 is fully depressed, the lock body 564 ofthe locking member 562 may engage a roof 583 c of the opening 583 tolimit depression of the button 580 and/or distal movement of the lockingmember 564.

Continuing to refer to FIG. 26, with the locking mechanism 560 in theunlocked position, the roll housing 520 is rotatable about the connector220. Rotation of the roll housing 520 also rotates the outer tube 270about the longitudinal axis A-A through the engagement of the roll nut550 with the roll housing 520.

It will be appreciated that when the roll housing 520 is rotatedrelative to the connector 220 with the lock cutouts 542 misaligned withthe lock 569 and the button 580 is released, the lock 569 will abut thelocking disc 540 until the lock 569 is aligned with one of the lockcutouts 542. When the lock 569 is aligned with one of the lock cutouts542, the biasing members 598 will urge the button 580 away from thelongitudinal axis A-A and affect proximal movement of the locking member562 such that the lock 569 will slide into the aligned lock cutout 542.When the lock 569 slides into the aligned lock cutout 542, the stop 567may contact the locking disc 540 to provide audible indicia (a “click”)that the roll housing 520 is rotationally secured to the connector 220.

While rotation of the roll housing 520 about the connector 220 isdetailed above, it is contemplated that the connector 220 may be rotatedwithin the roll housing 520 such that the tool assembly 600 isrepositionable relative to the handle 100 with the tool assembly 600remaining substantially stationary within a surgical site.

Any of the components described herein may be fabricated from eithermetals, plastics, resins, composites or the like taking intoconsideration strength, durability, wearability, weight, resistance tocorrosion, ease of manufacturing, cost of manufacturing, and the like.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Any combination ofthe above embodiments is also envisioned and is within the scope of theappended claims. Therefore, the above description should not beconstrued as limiting, but merely as exemplifications of particularembodiments. Those skilled in the art will envision other modificationswithin the scope of the claims appended hereto.

What is claimed:
 1. A joint assembly comprising: a proximal jointhousing having a distal portion and defining a first longitudinal axis,the proximal joint housing including a first hinge positioned on thedistal portion; a first ring pivotally coupled to the first hinge abouta first pivot axis orthogonal to and intersecting the first longitudinalaxis; a joint cover pivotally coupled to the first hinge about a secondpivot axis orthogonal to and intersecting the first pivot axis and thefirst longitudinal axis, the first and second pivot axes intersectingthe first longitudinal axis at a first joint center, the joint coverdefining a cover axis extending longitudinally therethrough; and abiasing mechanism operatively associated with the joint cover to biasthe joint cover towards an aligned configuration in which the cover axisis aligned with the first longitudinal axis.
 2. The joint assemblyaccording to claim 1, wherein the biasing mechanism includes a pair ofinner biasing bars and a pair of outer biasing bars, the pair of innerbiasing bars engaged with the first cover portion of the joint cover andthe pair of outer biasing bars engaged with the first ring.
 3. The jointassembly according to claim 2, wherein each of the inner and outerbiasing bars of the pairs of inner and outer biasing bars extendslongitudinally and is translatable in a direction parallel to the firstlongitudinal axis.
 4. The joint assembly according to claim 3, whereineach of the inner and outer biasing bars of the pairs of inner and outerbiasing bars is operably associated with a respective biasing memberthat is configured to urge the associated biasing bar through the firsthinge.
 5. The joint assembly according to claim 4, wherein the jointcover includes a first cover portion and a second cover portion and thejoint assembly further comprises a second ring pivotally coupled to thesecond cover portion of the joint cover about a third pivot axis and asecond hinge pivotally coupled to the second ring about a fourth pivotaxis orthogonal to the third pivot axis, the third and fourth pivot axesintersecting at a second joint center spaced from the first jointcenter, wherein the cover axis of the joint cover is defined between thefirst and second joint centers.
 6. The joint assembly according to claim5, wherein in an aligned configuration of the second hinge, a secondlongitudinal axis is aligned with the cover axis and the firstlongitudinal axis, the second longitudinal axis passing through thesecond joint center and extending through the center of the secondhinge.
 7. The joint assembly according to claim 6, wherein in a firstarticulated configuration of the joint assembly, the second longitudinalaxis is articulated relative to the cover axis with the joint cover inthe aligned configuration and in a second articulated configuration ofthe joint assembly, the second longitudinal axis is articulated relativeto the cover axis and the cover axis is articulated relative to thefirst longitudinal axis.
 8. The joint assembly according to claim 7,wherein the biasing mechanism is configured to maintain the jointassembly in the first articulated configuration until the secondlongitudinal axis is articulated to a maximum angle of articulationrelative to the cover axis.
 9. The joint assembly according to claim 8,wherein the maximum angle of articulation is in a range of 15° to 45°.10. The joint assembly according to claim 5, further comprising: a firstdrive shaft extending through the first hinge; a joint body having afirst body portion and a second body portion, the first body portionbeing rotatably disposed within the first cover portion and rotatablyand pivotally coupled to the first drive shaft, the second body portionbeing rotatably disposed within the second cover portion; and a seconddrive shaft extending through the second hinge, the second drive shaftrotatably and pivotally coupled to the second body portion.
 11. Thejoint assembly according to claim 10, wherein a drive ball of the firstdrive shaft is disposed within the first body portion.
 12. The jointassembly according to claim 11, wherein the first drive shaft isrotatably disposed along the first longitudinal axis, the drive balldefining a center channel orthogonal to the first longitudinal axis andarced slots in a plane aligned with the first longitudinal axis andbisecting the center channel.
 13. The joint assembly according to claim12, further comprising: a center pin disposed within the center channeland defining a pin opening orthogonal to a central longitudinal axis ofthe center pin; and a shaft pin disposed within the pin opening and thearced slots to rotatably couple the joint body to the first drive shaft.14. The joint assembly according to claim 13, wherein the arced slotsand the shaft pin cooperate to limit articulation between the firstdrive shaft and the joint body.
 15. The joint assembly according toclaim 10, wherein the second drive shaft further includes a receiver,the receiver being rotatably disposed within the second cover portionand receiving the second body portion.
 16. The joint assembly accordingto claim 15, wherein the cover axis passes through the first and secondjoint centers, the second body portion defining a center channelorthogonal to the cover axis and arced slots in a plane aligned with thecover axis and bisecting the center channel.
 17. The joint assemblyaccording to claim 16, wherein the joint body is rotatable along thecover axis.
 18. The joint assembly according to claim 17, furthercomprising: a center pin disposed within the center channel and defininga pin opening that is orthogonal to a central longitudinal axis of thecenter pin; and a shaft pin disposed within the pin opening and thearced slots to rotatably couple the joint body to the second driveshaft.
 19. The joint assembly according to claim 18, wherein the arcedslots and the shaft pin cooperate to limit articulation between thejoint body and the second drive shaft.
 20. An adapter comprising: aproximal portion; an elongate portion extending from the proximalportion and defining a first longitudinal axis; and a distal portionincluding a joint assembly supported by the elongate portion, the jointassembly having: a first hinge disposed along the first longitudinalaxis and positioned at a distal end of the elongate portion; a firstring pivotally coupled to the first hinge about a first pivot axisorthogonal to and intersecting the first longitudinal axis; a jointcover pivotally coupled to the first hinge about a second pivot axisorthogonal to and intersecting the first pivot axis and the firstlongitudinal axis, the first and second pivot axes intersecting thefirst longitudinal axis at a first joint center; and a biasing mechanismoperatively associated with the joint cover to bias the joint covertowards an aligned configuration in which the cover axis is aligned withthe first longitudinal axis.